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CVE

CVE-2026-35039

fast-jwt Affected by Cache Confusion via cacheKeyBuilder Collisions Can Return Claims From a Different Token (Identity/Authorization Mixup)
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CVE

CVE-2026-35039

fast-jwt Affected by Cache Confusion via cacheKeyBuilder Collisions Can Return Claims From a Different Token (Identity/Authorization Mixup)

fast-jwt provides fast JSON Web Token (JWT) implementation. From 0.0.1 to before 6.2.0, setting up a custom cacheKeyBuilder method which does not properly create unique keys for different tokens can lead to cache collisions. This could cause tokens to be mis-identified during the verification process leading to valid tokens returning claims from different valid tokens and users being mis-identified as other users based on the wrong token. Version 6.2.0 contains a patch.

Package Versions Affected

Package Version
patch Availability
No items found.

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CVSS Version

Severity
Base Score
CVSS Version
Score Vector
C
H
U
9.1
-
3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
C
H
U
0
-
3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
C
H
U
-

Related Resources

No items found.

References

https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/35xxx/CVE-2026-35039.json, https://github.com/nearform/fast-jwt/security/advisories/GHSA-rp9m-7r4c-75qg, https://nvd.nist.gov/vuln/detail/CVE-2026-35039, https://github.com/nearform/fast-jwt/commit/de121056c6415b58770c60640881eaec67ac4ceb

Severity

9.1

CVSS Score
0
10

Basic Information

Base CVSS
9.1
EPSS Probability
0.00212%
EPSS Percentile
0.11801%
Introduced Version
878469bd124161f35b43b38575f9d8a237c65061
Fix Available
de121056c6415b58770c60640881eaec67ac4ceb

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